Technology Field
The present disclosure relates generally to antenna apparatus for use in electronic devices such as wireless radio devices, and more particularly in one exemplary aspect to a capacitively coupled antenna apparatus, and methods of, inter alia, tuning and utilizing the same.
Description of Related Technology
Current trends in mobile wireless devices demand generally compact (e.g., thin) form factor devices with a large display. Along with these demands are operator requirements on FS (freespace) BHR/L (Beside Head Right/Left) and BHHR/L (Beside head hand right/Left) performance. Radio frequency tuners are currently being used to compensate for the antenna mismatch in beside head/hand scenarios. Typical prior art antennas are “tuned” for freespace, and the antenna thus detunes in the presence of the user's hand/head (i.e., a head/hand is a capacitive loading factor which causes detuning and mismatch of the antenna). An impedance tuner is then able to match the antenna back to a sufficient matching level. Thus, in the end, the total efficiency of the antenna in the hand/head use scenarios is equal to the total efficiency in freespace minus absorptive losses by the user's hand/head, minus the insertion loss of the tuner, and minus the mismatch loss.
The typical prior art tuner is able to remove the mismatch loss by improving the matching to the source impedance (typically 50 ohm). However, in the detuned case when the mismatch is large, the tuner also introduces a large insertion loss. Thus, the loss components include absorptive loss plus a significant insertion loss, which is not optimal.
Accordingly, there is a salient need for, inter alia, an improved antenna solution that can provide the required electrical and other performance attributes, yet with reduced insertion loss in such operational scenarios as those described above.